Pub Date : 2025-12-01Epub Date: 2025-09-19DOI: 10.1016/j.tube.2025.102693
Yufan Xu , Longlong Wang , Jijie Jiang , Guocheng Zhao , Zhe Wang
The rising prevalence of drug-resistant tuberculosis (DR-TB), coupled with stagnation in the development of novel therapeutics, underscores the urgent need for new drug targets and innovative anti-tuberculosis agents. In this study, we demonstrate that CRISPR interference-mediated knockdown of argH, a nitrogen metabolism-associated gene encoding argininosuccinate lyase, significantly impairs the growth of Mycolicibacterium smegmatis (formerly Mycobacterium smegmatis). This growth defect was alleviated in a concentration-dependent manner by arginine supplementation. In a goldfish infection model, argH knockdown led to a marked reduction in bacterial burden within both liver and kidney tissues. Notably, bacitracin and 5-fluorouracil exhibited synergistic effects when combined with argH knockdown. Metabolomic profiling revealed significant perturbations in multiple amino acids, as well as in succinyl-CoA and lactate levels, suggesting that suppression of argH impairs M. smegmatis proliferation by disrupting amino acid homeostasis and interfering with aerobic respiration.
{"title":"Knockdown of argininosuccinate lyase influences the growth of Mycolicibacterium smegmatis in vitro and in vivo","authors":"Yufan Xu , Longlong Wang , Jijie Jiang , Guocheng Zhao , Zhe Wang","doi":"10.1016/j.tube.2025.102693","DOIUrl":"10.1016/j.tube.2025.102693","url":null,"abstract":"<div><div>The rising prevalence of drug-resistant tuberculosis (DR-TB), coupled with stagnation in the development of novel therapeutics, underscores the urgent need for new drug targets and innovative anti-tuberculosis agents. In this study, we demonstrate that CRISPR interference-mediated knockdown of argH, a nitrogen metabolism-associated gene encoding argininosuccinate lyase, significantly impairs the growth of <em>Mycolicibacterium smegmatis</em> (formerly <em>Mycobacterium smegmatis</em>). This growth defect was alleviated in a concentration-dependent manner by arginine supplementation. In a goldfish infection model, argH knockdown led to a marked reduction in bacterial burden within both liver and kidney tissues. Notably, bacitracin and 5-fluorouracil exhibited synergistic effects when combined with argH knockdown. Metabolomic profiling revealed significant perturbations in multiple amino acids, as well as in succinyl-CoA and lactate levels, suggesting that suppression of argH impairs <em>M. smegmatis</em> proliferation by disrupting amino acid homeostasis and interfering with aerobic respiration.</div></div>","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102693"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-09-05DOI: 10.1016/j.tube.2025.102688
Promod K. Mehta, Jefry Sebastian
Diagnosis of extrapulmonary tuberculosis (EPTB) is challenging. During the last two decades, several nucleic acid amplification tests have been deliberated to diagnose TB (including EPTB) and drug resistance (DR), i.e. in-house PCR/multiplex-PCR, commercial real-time PCR (e.g. Cobas TaqMan/LightCycler), line probe assay (e.g. GenoType MTBDRplus), GeneXpert®/GeneXpert® Ultra and Truenat®MTB/MTB Plus (TruPlus). However, we still need a simple and reliable diagnostic test especially for remote areas. Markedly, both GeneXpert/Xpert Ultra require a constant power supply and their high cost is a major hindrance in resource-limited settings. To overcome this, Molbio Diagnostics, India, introduced a Truenat/TruPlus assay (the WHO endorsed), which is chip-based micro real-time PCR system that targets nrdB, while TruPlus targets IS6110+nrdZ for the identification of Mtb within 1 h. After a positive result, an ‘add-on’ chip, i.e. Truenat® MTB-RIF Dx (TruRif) is utilized to detect rifampicin-resistance (RIF-R) that takes another 1 h. Although there is adequate literature on the diagnosis of pulmonary TB by Truenat/TruPlus, limited information is available on EPTB diagnosis. In this review, we assessed the performance of Truenat/TruPlus in different EPTB types, i.e. TB lymphadenitis, TB pleuritis, TB meningitis, osteoarticular TB, etc. that exhibits moderate to good sensitivity/specificity. Meanwhile, few false negative/positive RIF-R results are obtained by TruRif. Since Truenat/TruPlus is portable, battery-operated and relatively cost-effective as compared to GeneXpert/Xpert Ultra, it can be utilized for preliminary screening of EPTB specimens in peripheral settings, which may be further confirmed by other tests.
{"title":"Diagnosis of extrapulmonary tuberculosis by Truenat® MTB/MTB Plus assay","authors":"Promod K. Mehta, Jefry Sebastian","doi":"10.1016/j.tube.2025.102688","DOIUrl":"10.1016/j.tube.2025.102688","url":null,"abstract":"<div><div>Diagnosis of extrapulmonary tuberculosis (EPTB) is challenging. During the last two decades, several nucleic acid amplification tests have been deliberated to diagnose TB (including EPTB) and drug resistance (DR), <em>i.e</em>. in-house PCR/multiplex-PCR, commercial real-time PCR (<em>e.g.</em> Cobas TaqMan/LightCycler), line probe assay (<em>e.g.</em> GenoType MTBDRplus), GeneXpert®/GeneXpert® Ultra and Truenat®MTB/MTB Plus (TruPlus). However, we still need a simple and reliable diagnostic test especially for remote areas. Markedly, both GeneXpert/Xpert Ultra require a constant power supply and their high cost is a major hindrance in resource-limited settings. To overcome this, Molbio Diagnostics, India, introduced a Truenat/TruPlus assay (the WHO endorsed), which is chip-based micro real-time PCR system that targets <em>nrdB</em>, while TruPlus targets IS<em>6110</em>+<em>nrdZ</em> for the identification of <em>Mtb</em> within 1 h. After a positive result, an ‘add-on’ chip, <em>i.e</em>. Truenat® MTB-RIF Dx (TruRif) is utilized to detect rifampicin-resistance (RIF-R) that takes another 1 h. Although there is adequate literature on the diagnosis of pulmonary TB by Truenat/TruPlus, limited information is available on EPTB diagnosis. In this review, we assessed the performance of Truenat/TruPlus in different EPTB types, <em>i.e</em>. TB lymphadenitis, TB pleuritis, TB meningitis, osteoarticular TB, etc. that exhibits moderate to good sensitivity/specificity. Meanwhile, few false negative/positive RIF-R results are obtained by TruRif. Since Truenat/TruPlus is portable, battery-operated and relatively cost-effective as compared to GeneXpert/Xpert Ultra, it can be utilized for preliminary screening of EPTB specimens in peripheral settings, which may be further confirmed by other tests.</div></div>","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102688"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper develops and analyzes a Caputo fractional-order mathematical model for tuberculosis (TB) transmission that incorporates testing, therapy, isolation, and treatment interventions. The model divides the population into five compartments—susceptible, exposed, infectious, isolated, and recovered—and its qualitative properties, including positivity, boundedness, existence, and uniqueness of solutions, are established. The basic reproduction number R0 is derived, and sensitivity analysis identifies transmission, progression, testing, and treatment rates as critical drivers of TB dynamics. Using the Laplace–Adomian decomposition method (LADM), numerical simulations are performed to assess the impact of fractional-order derivatives on disease spread and control. The results show that increasing the order of the fractional derivative enhances the accuracy of the model and reveals memory effects in TB dynamics. Moreover, early diagnosis, therapy, and isolation significantly reduce infection levels and improve recovery outcomes. These findings highlight the advantages of fractional-order models over classical approaches and provide valuable insights for designing effective TB control strategies.
{"title":"Analysis of tuberculosis infection dynamics using Caputo fractional-order models with diagnosis and treatment interventions","authors":"Oluwafemi Ezekiel Abiodun , Morufu Oyedunsi Olayiwola","doi":"10.1016/j.tube.2025.102694","DOIUrl":"10.1016/j.tube.2025.102694","url":null,"abstract":"<div><div>This paper develops and analyzes a Caputo fractional-order mathematical model for tuberculosis (TB) transmission that incorporates testing, therapy, isolation, and treatment interventions. The model divides the population into five compartments—susceptible, exposed, infectious, isolated, and recovered—and its qualitative properties, including positivity, boundedness, existence, and uniqueness of solutions, are established. The basic reproduction number R<sub>0</sub> is derived, and sensitivity analysis identifies transmission, progression, testing, and treatment rates as critical drivers of TB dynamics. Using the Laplace–Adomian decomposition method (LADM), numerical simulations are performed to assess the impact of fractional-order derivatives on disease spread and control. The results show that increasing the order of the fractional derivative enhances the accuracy of the model and reveals memory effects in TB dynamics. Moreover, early diagnosis, therapy, and isolation significantly reduce infection levels and improve recovery outcomes. These findings highlight the advantages of fractional-order models over classical approaches and provide valuable insights for designing effective TB control strategies.</div></div>","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102694"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145259218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-23DOI: 10.1016/j.tube.2025.102700
Alejandro Rivas-Castro , Itzel Rocío Manzano Espinosa , Diana Villa Sepúlveda , Eduardo Pablo Sánchez Martínez , José Alberto Choreño-Parra , Yaser Sánchez Gama , Ana Sofía Alonso Villaseñor , Fernando Daniel Argueta Muñoz , Erick Gómez Apo , Citlaltepetl Salinas-Lara , Carlos Sánchez-Garibay , Martha Lilia Tena Suck
Introduction
Central nervous system tuberculosis (CNS-TB) is the most lethal form of tuberculosis, characterized by severe clinical manifestations and distinctive histopathological changes. Although several cytokines are implicated in the immune response to Mycobacterium tuberculosis, their relationship with disease severity and histological alterations remains unclear. This study aimed to evaluate the associations between cytokine expression, histopathological changes, and clinical features in patients with CNS-TB.
Methods
We conducted a retrospective, observational, cross-sectional, descriptive study of 25 biopsies that fulfilled criteria for CNS-TB at the National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez.” Cases were classified according to the Suzaan Marais criteria. Immunohistochemistry was performed to assess IL-1β, IL-4, IL-10, IL-17, IL-23, TNF-α, and IFN-γ expression in meningeal and parenchymal tissues.
Results
Strong expression of IL-1β, IL-17, IL-23, and TNF-α was observed in glial cells, vascular endothelial cells, and macrophages, particularly within inflammatory and vascular lesions.
Conclusions
Although no direct correlation was found between cytokine expression and clinical severity, the findings support a predominant pro-inflammatory response mediated by IL-1β, IL-17, IL-23, and TNF-α, associated with tissue and vascular damage. The elevated cytokine expression in foam cells suggests a potential role in local immune regulation in CNS-TB.
{"title":"“The cytokine profiles of the inflammatory response in chronic granulomatous encephalitis caused by Mycobacterium tuberculosis do not influence the patient's clinical presentation\"","authors":"Alejandro Rivas-Castro , Itzel Rocío Manzano Espinosa , Diana Villa Sepúlveda , Eduardo Pablo Sánchez Martínez , José Alberto Choreño-Parra , Yaser Sánchez Gama , Ana Sofía Alonso Villaseñor , Fernando Daniel Argueta Muñoz , Erick Gómez Apo , Citlaltepetl Salinas-Lara , Carlos Sánchez-Garibay , Martha Lilia Tena Suck","doi":"10.1016/j.tube.2025.102700","DOIUrl":"10.1016/j.tube.2025.102700","url":null,"abstract":"<div><h3>Introduction</h3><div>Central nervous system tuberculosis (CNS-TB) is the most lethal form of tuberculosis, characterized by severe clinical manifestations and distinctive histopathological changes. Although several cytokines are implicated in the immune response to <em>Mycobacterium tuberculosis</em>, their relationship with disease severity and histological alterations remains unclear. This study aimed to evaluate the associations between cytokine expression, histopathological changes, and clinical features in patients with CNS-TB.</div></div><div><h3>Methods</h3><div>We conducted a retrospective, observational, cross-sectional, descriptive study of 25 biopsies that fulfilled criteria for CNS-TB at the National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez.” Cases were classified according to the Suzaan Marais criteria. Immunohistochemistry was performed to assess IL-1β, IL-4, IL-10, IL-17, IL-23, TNF-α, and IFN-γ expression in meningeal and parenchymal tissues.</div></div><div><h3>Results</h3><div>Strong expression of IL-1β, IL-17, IL-23, and TNF-α was observed in glial cells, vascular endothelial cells, and macrophages, particularly within inflammatory and vascular lesions.</div></div><div><h3>Conclusions</h3><div>Although no direct correlation was found between cytokine expression and clinical severity, the findings support a predominant pro-inflammatory response mediated by IL-1β, IL-17, IL-23, and TNF-α, associated with tissue and vascular damage. The elevated cytokine expression in foam cells suggests a potential role in local immune regulation in CNS-TB.</div></div>","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102700"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145393303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-11-21DOI: 10.1016/j.tube.2025.102706
Safiya Mehraj , Shazia Ali , Chetan Kumar , Asif Ali , Zahoor Ahmad
Background
Chronic inflammation fuels tissue damage and morbidity in numerous diseases, including Tuberculosis, underscoring the vital need for Host-Directed Therapies to safely modulate the exaggerated host response. We investigated the immunomodulatory potential of Sofalcone and Rebamipide alongside a novel Diaryl Ether derivative of Dehydrozingerone DHZ (6), hypothesizing that they exert therapeutic effects by targeting the central inflammatory driver, the NF-κB pathway.
Methods
We evaluated the safety and efficacy of the compounds in THP-1 macrophages infected with M. smegmatis. Mechanistic studies utilized Western blotting, immunofluorescence, and ELISA to track NF-κB activation. MMP activity was assessed by gelatin zymography, and ROS production was quantified using the DCFH-DA assay.
Results
All compounds exhibited low cytotoxicity and significantly reduced intracellular bacterial survival. Agents potently and consistently inhibited the NF-κB cascade, evidenced by ≈ 83 % suppression of upstream P-IKKα/IKKβ and up to ≈89 % reduction in p65 phosphorylation. This molecular blockade prevented p65 nuclear translocation and resulted in a downstream functional benefit: near total abolition of MMP-2/9 activity and ≈71 % mitigation of ROS production.
Conclusion
Our results unequivocally validate NF-κB inhibition by DHZ (6), Sofalcone, and Rebamipide as a powerful strategy for HDT. These compounds are promising adjunct therapies to suppress host inflammation and limit tissue damage.
{"title":"Inhibition of mycobacteria proliferation in macrophages by diaryl ether derivatives of Dehydrozingerone compound and repurposed drugs (Rebamipide, Sofalcone) via NF-κB pathway inhibition","authors":"Safiya Mehraj , Shazia Ali , Chetan Kumar , Asif Ali , Zahoor Ahmad","doi":"10.1016/j.tube.2025.102706","DOIUrl":"10.1016/j.tube.2025.102706","url":null,"abstract":"<div><h3>Background</h3><div>Chronic inflammation fuels tissue damage and morbidity in numerous diseases, including Tuberculosis, underscoring the vital need for Host-Directed Therapies to safely modulate the exaggerated host response. We investigated the immunomodulatory potential of Sofalcone and Rebamipide alongside a novel Diaryl Ether derivative of Dehydrozingerone DHZ (6), hypothesizing that they exert therapeutic effects by targeting the central inflammatory driver, the NF-κB pathway.</div></div><div><h3>Methods</h3><div>We evaluated the safety and efficacy of the compounds in THP-1 macrophages infected with <em>M. smegmatis.</em> Mechanistic studies utilized Western blotting, immunofluorescence, and ELISA to track NF-κB activation. MMP activity was assessed by gelatin zymography, and ROS production was quantified using the DCFH-DA assay.</div></div><div><h3>Results</h3><div>All compounds exhibited low cytotoxicity and significantly reduced intracellular bacterial survival. Agents potently and consistently inhibited the NF-κB cascade, evidenced by ≈ 83 % suppression of upstream P-IKKα/IKKβ and up to ≈89 % reduction in p65 phosphorylation. This molecular blockade prevented p65 nuclear translocation and resulted in a downstream functional benefit: near total abolition of MMP-2/9 activity and ≈71 % mitigation of ROS production.</div></div><div><h3>Conclusion</h3><div>Our results unequivocally validate NF-κB inhibition by DHZ (6), Sofalcone, and Rebamipide as a powerful strategy for HDT. These compounds are promising adjunct therapies to suppress host inflammation and limit tissue damage.</div></div>","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102706"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-14DOI: 10.1016/j.tube.2025.102695
Promod K. Mehta
{"title":"Letter to Editor: manuscript entitled “Utility of pleural fluid-derived extracellular vesicles as a source of Mycobacterium tuberculosis antigens MPT51 and MPT64 for pleural TB diagnosis: a proof-of-concept study” by Jindal et al. published in Tuberculosis150 (2025) 102578","authors":"Promod K. Mehta","doi":"10.1016/j.tube.2025.102695","DOIUrl":"10.1016/j.tube.2025.102695","url":null,"abstract":"","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102695"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145313725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-11-15DOI: 10.1016/j.tube.2025.102707
Sudhasini Panda , Catherine Cheng , Naomi Hillery , Donald G. Catanzaro , Nelly Ciobanu , Valeriu Crudu , Timothy Rodwell , Antonino Catanzaro , Julie G. Burel , Bjoern Peters , Cecilia S. Lindestam Arlehamn
Understanding the perturbations in immune response across the spectrum of TB infection is still unclear. Here, we followed close contacts of pulmonary TB patients with serial QFT testing at 0, 3, 6, and 12 months, and stratified them into six subgroups: QFT-increasing (low/high), QFT-converters (QFT-to QFT+), QFT + stable, and QFT-individuals. Despite these distinct QFT trajectories, we observed minimal differences in immune cell frequencies, activation profiles, and T-helper subset distributions among QFT subgroups, suggesting limited immunological stratification based on QFT dynamics. Ex vivo immune phenotyping, including CD4, CD8, NKT cell frequencies, memory T-cell subsets, and activated T-cells (HLA-DR+CD38+), failed to distinguish between QFT subgroups, suggesting blood-based immune profiling may not capture subtle immunological transitions among different QFT subgroups. Active TB (ATB) patients showed marked immune alterations, with elevated antigen-specific CD4 T-cells, activated T cells, intermediate monocytes, NK cells at-diagnosis, which declined following treatment, indicating immune recovery. This suggest, while ex vivo immune profiling effectively distinguishes ATB from non-diseased states, it lacks the sensitivity to resolve QFT-based subgroups. Findings suggest either immune similarity among close contacts regardless of QFT status or limits of blood-based profiling in detecting early changes, underscoring the difficulty of distinguishing QFT subgroups with conventional ex vivo approaches.
{"title":"Minimal immune cell subset differences in a cohort of close contacts of tuberculosis index cases","authors":"Sudhasini Panda , Catherine Cheng , Naomi Hillery , Donald G. Catanzaro , Nelly Ciobanu , Valeriu Crudu , Timothy Rodwell , Antonino Catanzaro , Julie G. Burel , Bjoern Peters , Cecilia S. Lindestam Arlehamn","doi":"10.1016/j.tube.2025.102707","DOIUrl":"10.1016/j.tube.2025.102707","url":null,"abstract":"<div><div>Understanding the perturbations in immune response across the spectrum of TB infection is still unclear. Here, we followed close contacts of pulmonary TB patients with serial QFT testing at 0, 3, 6, and 12 months, and stratified them into six subgroups: QFT-increasing (low/high), QFT-converters (QFT-to QFT+), QFT + stable, and QFT-individuals. Despite these distinct QFT trajectories, we observed <strong>minimal differences in immune cell frequencies, activation profiles, and T-helper subset distributions among QFT subgroups,</strong> suggesting limited immunological stratification based on QFT dynamics. Ex vivo immune phenotyping, including CD4, CD8, NKT cell frequencies, memory T-cell subsets, and activated T-cells (HLA-DR<sup>+</sup>CD38<sup>+</sup>), failed to distinguish between QFT subgroups, suggesting blood-based immune profiling may not capture subtle immunological transitions among different QFT subgroups. Active TB (ATB) patients showed marked immune alterations, with elevated antigen-specific CD4 T-cells, activated T cells, intermediate monocytes, NK cells at-diagnosis, which declined following treatment, indicating immune recovery. This suggest, while ex vivo immune profiling effectively distinguishes ATB from non-diseased states, it lacks the sensitivity to resolve QFT-based subgroups. Findings suggest either immune similarity among close contacts regardless of QFT status or limits of blood-based profiling in detecting early changes, underscoring the difficulty of distinguishing QFT subgroups with conventional ex vivo approaches.</div></div>","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102707"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145550934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mycobacterium tuberculosis (M. tuberculosis) persists within macrophages by evading phagosome maturation. In this study, we considered the role of actin dynamics in this process. Macrophages infected with virulent M. tuberculosis showed high F-actin/G-actin ratio, accompanied by reduced expression of the actin-depolymerizing protein cofilin1 and increased levels of its inactive phosphorylated form. Overexpression of a constitutively active cofilin1 variant reduced F-actin accumulation and enhanced phagosome acidification. Similar effects were observed with sorafenib, a PI3K-dependent activator of cofilin1, which decreased F-actin levels and promoted phagosome acidification in infected macrophages. Ectopic expression of the mycobacterial virulence factor ESAT-6 in macrophages led to cofilin1 downregulation. ESAT-6 also increased F-actin, altered cell morphology and impaired phagosome acidification in infections with avirulent M. tuberculosis strain. As cofilin1 is positively regulated by reactive oxygen species (ROS), we examined the role of methionine in ESAT-6-mediated ROS suppression. Mutation of methionine 93 in ESAT-6 increased intracellular ROS, enhanced phagosome acidification, and decreased F-actin levels. These findings reveal that M. tuberculosis impairs phagosome acidification by modulating host actin dynamics at least partially through ESAT-6–mediated suppression of cofilin1 and ROS. Enhancing cofilin1 activity may represent a potential therapeutic strategy to restore phagosome function and improve bacterial clearance, more specifically during the initial establishment of infection.
{"title":"ESAT-6 of Mycobacterium tuberculosis downregulates cofilin1, leads to filamentous actin enrichment and reduces the phagosome acidification in infected macrophages, which are partially reversed by a single methionine mutation","authors":"P.P. Mahesh , R.J. Retnakumar , K.C. Sivakumar , Sathish Mundayoor","doi":"10.1016/j.tube.2025.102680","DOIUrl":"10.1016/j.tube.2025.102680","url":null,"abstract":"<div><div><em>Mycobacterium tuberculosis</em> (<em>M. tuberculosis</em>) persists within macrophages by evading phagosome maturation. In this study, we considered the role of actin dynamics in this process. Macrophages infected with virulent <em>M. tuberculosis</em> showed high F-actin/G-actin ratio, accompanied by reduced expression of the actin-depolymerizing protein cofilin1 and increased levels of its inactive phosphorylated form. Overexpression of a constitutively active cofilin1 variant reduced F-actin accumulation and enhanced phagosome acidification. Similar effects were observed with sorafenib, a PI3K-dependent activator of cofilin1, which decreased F-actin levels and promoted phagosome acidification in infected macrophages. Ectopic expression of the mycobacterial virulence factor ESAT-6 in macrophages led to cofilin1 downregulation. ESAT-6 also increased F-actin, altered cell morphology and impaired phagosome acidification in infections with avirulent <em>M. tuberculosis</em> strain. As cofilin1 is positively regulated by reactive oxygen species (ROS), we examined the role of methionine in ESAT-6-mediated ROS suppression. Mutation of methionine 93 in ESAT-6 increased intracellular ROS, enhanced phagosome acidification, and decreased F-actin levels. These findings reveal that <em>M. tuberculosis</em> impairs phagosome acidification by modulating host actin dynamics at least partially through ESAT-6–mediated suppression of cofilin1 and ROS. Enhancing cofilin1 activity may represent a potential therapeutic strategy to restore phagosome function and improve bacterial clearance, more specifically during the initial establishment of infection.</div></div>","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102680"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Toxin antitoxin (TA) systems are bicistronic genetic elements encoding for a stable toxin and its cognate labile antitoxin. The genome of Mycobacterium tuberculosis (M. tuberculosis) encodes a large repertoire of TA systems and these are highly conserved in members of the M. tuberculosis complex. In the present study, we have characterised PezAT and MbcTA TA systems from M. tuberculosis. We show that the transcript levels of toxins and antitoxins belonging to PezAT and MbcTA were increased in M. tuberculosis exposed to oxidative stress, nitrosative stress and rifampicin. We also show that the relative levels of precursors for the peptidoglycan biosynthesis were increased in the PezT overexpression strain of M. smegmatis relative to uninduced cultures. Here, we have used temperature-sensitive mycobacteriophages to generate ΔpezAT and ΔmbcT mutant strains of M. tuberculosis. We demonstrate that the deletion of pezAT reduced the growth of M. tuberculosis upon exposure to detergent stress or rifampicin. However, the deletion of mbcT does not affect M. tuberculosis growth in various stress conditions. We also report that both PezAT and MbcT are dispensable for M. tuberculosis growth in macrophages and guinea pigs. Overall, these findings suggest that functional redundancy exists between TA systems.
{"title":"Understanding the role of PezAT and MbcTA toxin-antitoxin systems in the pathophysiology of Mycobacterium tuberculosis","authors":"Manisha Singh , Deepika Chaudhary , Arun Sharma, Sonu Kumar Gupta, Imran Ahmad, Yashwant Kumar, Ramandeep Singh","doi":"10.1016/j.tube.2025.102703","DOIUrl":"10.1016/j.tube.2025.102703","url":null,"abstract":"<div><div>Toxin antitoxin (TA) systems are bicistronic genetic elements encoding for a stable toxin and its cognate labile antitoxin. The genome of <em>Mycobacterium tuberculosis</em> (<em>M. tuberculosis</em>) encodes a large repertoire of TA systems and these are highly conserved in members of the <em>M. tuberculosis</em> complex. In the present study, we have characterised PezAT and MbcTA TA systems from <em>M. tuberculosis.</em> We show that the transcript levels of toxins and antitoxins belonging to PezAT and MbcTA were increased in <em>M. tuberculosis</em> exposed to oxidative stress, nitrosative stress and rifampicin. We also show that the relative levels of precursors for the peptidoglycan biosynthesis were increased in the PezT overexpression strain of <em>M. smegmatis</em> relative to uninduced cultures. Here, we have used temperature-sensitive mycobacteriophages to generate Δ<em>pezAT</em> and Δ<em>mbcT</em> mutant strains of <em>M. tuberculosis</em>. We demonstrate that the deletion of <em>pezAT</em> reduced the growth of <em>M. tuberculosi</em>s upon exposure to detergent stress or rifampicin. However, the deletion of <em>mbcT</em> does not affect <em>M. tuberculosis</em> growth in various stress conditions. We also report that both PezAT and MbcT are dispensable for <em>M. tuberculosis</em> growth in macrophages and guinea pigs. Overall, these findings suggest that functional redundancy exists between TA systems.</div></div>","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102703"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145525596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-09-06DOI: 10.1016/j.tube.2025.102689
Vandana Singh , Mohd Mustkim Ansari , Debashis Dutta , R.S. Rajmani , Amit Singh , Bhupendra N. Singh
FadR, a GntR family transcriptional regulator, is known to maintain fatty acid homeostasis in prokaryotes. In this study, a fadR deletion mutant was generated in Mycobacterium bovis, which exhibited distinct morphological changes, along with enhanced permeability and increased antibiotic susceptibility. Interrupted cell-wall homeostasis often leads to such collateral phenotype. To gain insight into the lipid profile, we conducted lipidomics analysis, which revealed that the levels of DAT and PAT were higher in the mutant, while keto-mycolate methyl esters were lower. Further, key proteins responsible for altered phenotypes and lipid profiles were identified using a comparative proteomics approach between M. bovis and the ΔfadR mutant. In addition to lipid metabolism, several intermediary metabolic and stress response proteins predicted to have roles in the growth, survival, and pathogenicity of mycobacteria were also altered in the mutant. Notably, deletion of fadR led to hypervirulence in the animal model. Taken together, this study establishes a crucial role of FadR in the survival of mycobacteria by regulating lipid metabolism, providing insights into its potential as a target for therapeutic strategies against slow-growing mycobacteria.
{"title":"M. bovis FadR mutant exhibits an altered colony morphotype and increased virulence","authors":"Vandana Singh , Mohd Mustkim Ansari , Debashis Dutta , R.S. Rajmani , Amit Singh , Bhupendra N. Singh","doi":"10.1016/j.tube.2025.102689","DOIUrl":"10.1016/j.tube.2025.102689","url":null,"abstract":"<div><div>FadR, a GntR family transcriptional regulator, is known to maintain fatty acid homeostasis in prokaryotes. In this study, a <em>fadR</em> deletion mutant was generated in <em>Mycobacterium bovis</em>, which exhibited distinct morphological changes, along with enhanced permeability and increased antibiotic susceptibility. Interrupted cell-wall homeostasis often leads to such collateral phenotype. To gain insight into the lipid profile, we conducted lipidomics analysis, which revealed that the levels of DAT and PAT were higher in the mutant, while keto-mycolate methyl esters were lower. Further, key proteins responsible for altered phenotypes and lipid profiles were identified using a comparative proteomics approach between <em>M. bovis</em> and the Δ<em>fadR</em> mutant. In addition to lipid metabolism, several intermediary metabolic and stress response proteins predicted to have roles in the growth, survival, and pathogenicity of mycobacteria were also altered in the mutant. Notably, deletion of <em>fadR</em> led to hypervirulence in the animal model. Taken together, this study establishes a crucial role of FadR in the survival of mycobacteria by regulating lipid metabolism, providing insights into its potential as a target for therapeutic strategies against slow-growing mycobacteria.</div></div>","PeriodicalId":23383,"journal":{"name":"Tuberculosis","volume":"155 ","pages":"Article 102689"},"PeriodicalIF":2.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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